How to validate if the body of the angular form starts and ends with particular string

I've to take input from the user that starts with a particular string let's say XYZ and has business data in between and ends with ENDXYZ within the textview and I'm using angular framework for the UI

<div class="mb-3 col-md-5">
        <label for="bodyData" class="form-label">Body <span class="text-danger">*</span></label>
        <div class=wrapper>
          <textarea class="form-control" formControlName="bodyData"> </textarea>
        </div>
</div>

the ts part:

bodyData: ['',
        Validators.required
      ]

I thought I may use regex for the validation but I'm new to the angular framework so looking if there are any better ways to achieve it.

You can simply do this using inbuilt angular pattern validation.

    bodyData: ['', 
    [Validators.required, Validators.pattern(^XYZ.*\.XYZ$)]
    ]

Method 1:You can directly check inline:

 bodyData: ['',
        Validators.required, Validators.pattern(`your_pattern`)
      ]

Method 2: You can create a custom validator and check for your scenario:

In your ts:

import {MatchStringValidator} from './match-validator';
....
bodyData: ['',
        Validators.required
      ]

Validator:

import {Validator} from @angular/forms;

export class MatchStringValidator implements Validator {
    validate(string) {
     // regex logic to match your criteria
  }

you probably want https://angular.io/api/forms/Validators#pattern

you can also write custom validators. it's just an arrow function with a single control argument, returning an object object with errors if any

export declare interface ValidatorFn {
    (control: AbstractControl): ValidationErrors | null;
}